Bearing assembly with sensors for monitoring loads

ABSTRACT

A bearing assembly which couples a road wheel to a suspension system component on an automotive vehicle includes a hub to which the wheel is attached and a housing which is attached to the suspension system component. The housing has two tapered raceways which surround raceways on cones that are fitted on the hub. Organized in two rows between the raceways of the housing and cones are tapered rollers which roll along the raceways when the wheel rotates. The rollers as they pass over the outer raceway impart minute flexures to the housing and these flexures are monitored by multiple strain sensors on the housing. The strains—and the signals produced by the sensors—reflect conditions at the region of contact between a tire on the road wheel and the road surface over which the tire rolls. When the bearing assembly is used in industrial applications, such as rolling mills or machine tools, the electrical signals generated by the sensors provide indications usable by electronic processors and controllers which analyze these signals to determine the loads placed upon various components within a system which incorporates the bearing assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation-In-Part of application Ser. No. 09/547,129 filedApr. 10, 2000 now abandoned.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

This invention relates in general to bearings and, more particularly, toa bearing assembly which monitors forces and torques transmitted throughit to provide electrical signals for use by devices which monitor andcontrol vehicular dynamics based upon calculated tire patch loading orto determine the general stresses, strains, and loads placed upon abearing.

There are a number of applications where the loads and types of loadsplaced on a bearing in operation can provide significant informationabout the bearing and the objects attached to the bearing. One suchapplication is in the automotive industry where such loadinginformation, in electrical signal form, is vital for the properapplication of Vehicular Dynamic Control (“VDC”) systems. Anotherapplication is in the steel rolling mill industry where electronicprocessing and control is used to manipulate the speed and torque ofrollers during the rolling process. Yet another application is themachine tool industry where programmable controllers and processorsmonitor and control the speed of spindles in milling, cutting, anddrilling machines.

In the automotive industry, many vehicles of current manufacture comeequipped with antilock braking systems. A system of this type monitorsthe rotation of the wheels on a vehicle and, when the brakes of thevehicle are applied, relaxes the breaking force at any wheel which locksup and skids. This reduces the tendency of the vehicle to veer offcourse when the traction at the wheels differs and makes the vehicleeasier to steer under such circumstances. A few vehicles have tractioncontrol systems. This type of system monitors the rotation of drivenwheels and distributes the tractive effort between those wheels, so thatone does not break loose and spin. While both systems enable the driverof a vehicle to maintain better control over the vehicle, other factorsinfluence the operation of the vehicle and, notwithstanding thesuccessful operation of an antilock braking system and a tractioncontrol system, those other factors may still cause a vehicle to go outof control.

Significant among those other factors are the centrifugal forcesencountered by a vehicle when it negotiates a turn—forces which actlaterally on the vehicle. The friction between the vehicle tires and theroad surface, that is at the so-called “tire contact patches”, resiststhese forces, but sometimes the friction may not be enough and thevehicle will slide, and perhaps go out of control, particularly ifoperated by one having poor driving skills. Then again, the frictionalforces at the tire contact patches may prevent sliding, but thecentrifugal force generated by the turn, inasmuch as it acts at thecenter of gravity, which is above the tire contact patches, may besufficient to topple the vehicle.

Automobile manufactures have turned to VDC systems to preventautomobiles from going out of control in turns. The typical VDC systemrelies on a yaw sensor which measures the rate of change in yaw(rotation of the vehicle about its vertical axis) and a lateralacceleration sensor to, in effect, measure the centrifugal force imposedon the vehicle as a consequence of negotiating the turn. A VDC systemalso takes into account the angular velocity of the road wheels, theposition of the steering wheel, and the power delivered by the engine.The typical VDC system analyzes the information and modulates theoperation of the engine, as well as the brakes, to better maintaincontrol of the vehicle in the turn.

The more sophisticated VDC systems also factor into the real timeanalysis estimated loads at the individual wheels and thus seek toevaluate conditions at the tire contact patches. But when negotiating aturn, each tire contact patch experiences forces and torques that do notcomport with simle analytical procedures. Thus, measuring thedisplacement of a shock absorber piston, for example, does not give avery reliable indication of conditions that exist at the tire contactpatch below that shock absorber. Certainly, it provides no indication ofthe torque at the tire contact patch, much less of the location at whichthe resultant of the force at the tire contact patch is acting.

Bearing assemblies exist which incorporate the use of strain gages toprovide certain information regarding various bearing loads. Forexample, an antifriction rolling bearing disclosed in U.S. Pat. No.5,140,849 issued Aug. 25, 1992, uses two strain gages to monitor thegeneral loads applied to a bearing. This bearing, however, is unable toprovided the multi-faceted data needed by high level VDC electronicsystems or by the processor controlled systems in the rolling millsindustry or the machine tool industry.

U.S. Pat. No. 4,748,844 discloses a load detection device more relatedto the automotive industry. That device consists of a multi-componentload cell structure fixed to a hub on which a road wheel is mounted, theload cell structure being attached so as to rotate with the tire of thewheel. While that device provides some signal benefits, this devicecannot provide signals indicating all loads and all torques required toenable a high level VDC electronic device to function properly. Inparticular, that device mounts all of its strain gages in only one planewhich is perpendicular to the axis about which the wheel rotates. As aresult, the signals from the strain gages on that device are unable todetect the forces tending to cause a vehicle to skid sideways or to rollthe vehicle over.

Therefore, while the automotive industry is continuing to developelectronic devices which assist the driver to maintain control of hisvehicle through various combinations of brake application and continuoussuspension adjustment, the more sophisticated of these systems requirereliable input signals indicating the full spectrum of loading which areindicative of the loads exerted at the tire contact patch.

Similarly, the rolling mill and machine tool industry utilize variousforms of process controls which require monitoring of the loads placedon bearings. Specifically, rolling mills need bearing feedback regardingindications of belt slipping on rollers or indications that a particularset of rollers is experiencing higher loads and torques. Computercontrolled machine tools need to monitor the amount of torque beingexperienced by a bearing supporting a spindle in order to assess whethercutting and drilling tools have becomes dull or whether the cutting ordrilling speeds exceed the limits established for proper machiningoperations.

SUMMARY OF THE INVENTION

The present invention resides in a bearing assembly that couples a roadwheel to a suspension system component on an automotive vehicle. Thebearing assembly includes a hub to which the road wheel is attached anda housing which is attached to the suspension system component. The hubrotates in the housing on rolling elements which are arranged in tworows, with each row being between opposed raceways on the but andhousing. The rolling elements impart minute flexures to the housing, andthe flexures are detected by strain sensors attached to the housing. Inone embodiment the sensors are located at 90° intervals around eachraceway of the housing. In another they are on a flange at which thehousing is attached to the suspension system component. In still anotherthey are located along an intervening surface that lies between the tworaceways of the housing. The invention also resides in the bearingassemblies of the several embodiments apart from a wheel and suspensionsystem component. Additionally, the present invention resides in abearing assembly equipped with strain sensors used to generateelectrical signals of a type and mode which are usable by various typesof electronic processing and controlling devices which require suchelectrical signals to calculate loads within the mechanical system inwhich the bearing is incorporated.

The invention also resides in the method of using strain sensors togenerate electrical signals of a type and mode which are usable by otherautomotive devices which function to provide dynamic control of avehicle under various loading conditions, or by other electronic devicesin the rolling mill industry or the machine tool industry.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a road wheel showing the several forcesand torques that act on it;

FIG. 2 is a sectional view of a bearing assembly constructed inaccordance with and embodying the present invention;

FIG. 3 is a plan view of one of the sensor modules for the bearingassembly;

FIG. 4 is a plan view of a sensor for the sensor module of FIG. 3;

FIG. 5 is a perspective view of the housing for the bearing assembly;

FIG. 6 is an end view of a housing for a modified bearing assembly;

FIG. 7 is an expanded view showing the sensor modules of the modifiedbearing assembly in a single plane; and

FIG. 8 is an end view of a housing for another modified bearingassembly;

DETAILED DESCRIPTION

Referring now to the drawings, a road wheel W (FIG. 1), which supportsan automotive vehicle on a road surface, experiences several forces Fand torques T when the wheel W rolls along the road surface. First thereis the vertical force F_(v) which generally represents the weight of thevehicle and any inertial forces generated by irregularities in the roadsurface and by braking. The wheel W also experiences horizontal forcesF_(h) which act generally in the direction the wheel is headed. Also,there are thrust loads F_(t), which are forces directed axially, that isin the direction on the axis X of rotation. Then there is the verticaltorque T_(v), that is to say, torque about an axis passing verticallythrough the wheel W and sometimes referred to as the steering torque.Finally, horizontal torque T_(h), sometimes referred to as theoverturning moment, which acts about an axis passing horizontallythrough the wheel W in the direction of advance for the wheel W.Altogether the current invention measures the loads for five degrees offreedom which include three forces, F_(v), F_(h), and F_(t), and twomoments, T_(v) and T_(h).

The wheel W has a rim 2 and a tire 4 mounted on the rim 2. The tire 4contacts the road surface along a tire contact patch 6, where the tire 4experiences the forces F and torques T. The magnitude of the forces andtorques indicate conditions at the tire contact patch 6 and, whenevaluated with other conditions in real time, provide a goodrepresentation of the capacity of the vehicle to remain under control,or, on the other hand, go out of control.

The wheel W is coupled to a component C (FIG. 2) of the suspensionsystem for the vehicle at a bearing assembly A which enables the wheel Wto rotate about the axis X while transferring loads between the wheel Wand suspension system component C. Typically, the suspension systemcomponent C is a steering knuckle. The bearing assembly A includes a hub12 to which the wheel W is attached, a housing 14 which is secured tothe suspension system component C, and a bearing 16 which is locatedbetween the hub 12 and housing 14 and enables the hub 12 to rotate onthe housing 14 with minimal friction. To accommodate the housing 14, thesuspension system component C is provided with a through bore 18 and amachined end face 20. For the most part, the housing 14 fits partiallyinto the bore 18 and against the end face 20. The bearing 16 iscontained within the housing 14. The hub 12 extends into the bearing 16where is is confined both axially and radially.

More specifically, the hub 12 includes a flange 26 and a hollow spindle28 which projects from the flange 26 at a shoulder 30 located on theback face of the flange 26. Outwardly from the shoulder 30, the flange26 is fitted with lug bolts 32 which project axially from its other faceand pass through the rim 2 of the road wheel W. Beyond the wheel W, lugnuts 34 are threaded over the bolts 32 to secure the wheel W to the hub12.

At its end remote from the flange 26, the spindle 28 is upset, that is,deformed outwardly in the provision of a formed end 36 having anabutment face 38 that lies perpendicular to the axis X and is presentedtoward the shoulder 30. The bearing 16 is captured between the shoulder30 on the flange 26 and the face 38 of the formed end 36.

The bearing 16 includes an inner race in the form of two cones 40 whichfit around the spindle 28, there being an interference fit between eachcone 40 and the spindle 28. Each cone 40 has a tapered raceway 42 thatis presented outwardly away from the axis X, a thrust rib 44 at thelarge end of its raceway 42, and a back face 46, which is squared offwith respect to the axis X on the end of the thrust rib 44. The inboardcone 40 is somewhat longer than the outboard cone 40 by reason of acylindrical cone extension 48 which projects beyond the small end of itsraceway 42. The cone extension 48 may serve as a seat for a target wheelthat is monitored by a speed sensor in the housing 14. The inboard cone40 at its cone extension 48 abuts the small end of the outboard cone 40along the spindle 28, that is to say, the two cones 40 abut at theirfront faces. The back face 46 of the outboard cone 40 abuts the shoulder30 that lies along the flange 16, whereas the back face 46 of theinboard cone 40 abuts the end face 38 on the formed end 36.

In addition to the cones 40, the bearing 16 includes tapered rollers 54arranged in two rows, there being a separate row around each cone 40.Actually, the rollers 54 extend around the raceways 42 for the cones 40,there being essentially line contact between the tapered side faces ofthe rollers 54 and the raceways 42. The large end faces of the rollers54 bear against the thrust ribs 46. The rollers 54 of each row areessentially on apex, which means that the envelopes in which theirtapered side faces lie have their apices located at a common point alongthe axis X. Each row of rollers 54 has a cage 56 to maintain the properspacing between the rollers 54 in that row.

The housing 14 surrounds the spindle 28 as well as the two cones 40 andthe two rows of rollers 54. It forms part of the bearing 16 in that ishas tapered raceways 58 which are presented inwardly toward the axis X.In that sense, the housing 14 constitutes the outer race of the bearing16. The raceways 58 on the housing 14 tape downwardly toward acylindrical intervening surface 59 which separates them. The rollers 54likewise lie along the raceways 58 of the housing 14, there beingessentially line contact between the raceways 58 and the tapered sidefaces of the rollers 54. At their large ends, the raceways 58 open intoshort end bores 60 in which the thrust ribs 44 of the two cones 40 arelocated. Thus, each end of the bearing 16 has an annular space, withthat space being between the thrust rib 44 at that end and thesurrounding surface of the end bore 60.

The housing 14 has an exterior surface 62 that is generally cylindricaland also a triangular or rectangular flange 64 that projects from thesurface 62 generally midway between its ends. In the region behind theflanged 64, the diameter of the surface 62 is slightly less than thediameter of the through bore 18 in the suspension system component C.This portion of the housing 14 fits into the bore 18 with someclearance, while the back face of the flange 64 bears against the endface 20 on the component C. The housing 14 is secured firmly to thecomponent C with bolts 66 that pass through the latter and tread intothe flange 64 on the former.

The annular spaces at the ends of the bearing 16 are closed with seals68 which fit into the end bores 60 of the housing 14 and around thethrust ribs 44 of the cones 40. U.S. Pat. No. 5,022,659 disclosessuitable seals for both locations.

The formed end 36 unitizes the assembly A. But the hub 12 does notalways have the formed end 36. Initially, the spindle 28 of the hub 12extends from the shoulder 30 all the way to its free end as acylindrical surface. The two cones 40, with their complements of rollers54 and with the housing 14 captured between the rollers 54 of the tworows, are installed over the cylindrical surface of the spindle 28 andadvanced until the back face 46 of the outboard cone 40 comes againstthe shoulder 30 at the other end of the spindle 28. When the cones 40are so positioned, a portion of the spindle 28 projects beyond the backface 46 of the inboard cone 40. This portion is deformed into the formedend 36. PCT application GB 98/01823 (International Publication No.WO98/58762) discloses a rotary forming process for upsetting theinitially extended end of the spindle 28 and converting that end intothe integral formed end 36 which in effect unitizes the entire assemblyA.

Other means may secure the two cones 40 on the spindle 28 as well. Forexample, the end of the spindle 28 may have threads and a nut engagedwith those threads and turned down against the back face 46 of theinboard cone 40.

When the assembly A is so unitized, its bearing 16 exists in a conditionof slight preload. Actually the spacing between the inner raceways 42 onthe cones 40 determines the setting of the bearing 16, and that spacingdepends on the length of the cone extension 48 for the inboard cone 40,inasmuch as the rotary forming procedure which produces the formed end46 drives the inboard cone 40 toward the outboard cone 40 with enoughforce to cause the cone extension 48 on the former to abut the small endof the latter. A nut threaded over the spindle 28 and turned down snuglyagainst the back face 46 of the inboard cone 40 will have the sameeffect.

The forces F_(v), F_(h) and F_(t) and the torques T_(v) and T_(h) whichact upon the wheel W reflect conditions at the tire contact patch 6. Forexample, a balanced thrust load F_(t) will reflect travel in a straightline and will represent somewhat more than the preload in the bearing16. On the other hand, a larger unbalanced thrust F_(t), that is more inone direction than the other, will indicate a turn or perhaps asignificant inclination of the vehicle to one side or the other. Anincrease in the vertical force F_(v) will reflect a turn or theapplication of brakes if the wheel W is at the front of the vehicle.

The forces F_(v), F_(h), F_(t) and the torques T_(v) and T_(h) which thewheel W experiences are transferred to the suspension system component Cthrough the bearing assembly A, so the bearing assembly A experiencesthose forces F and torques T as well. The forces F and torque T manifestthemselves in minute expansions and contractions of the housing 14, andthese minute expansions and contractions are detected at sensor modulesM (FIG. 5) which are attached to the exterior surface 62 of the housing14 immediately outwardly from both its raceways 58. Actually, thetapered rollers 54 transfer the forces F and torques T from the cones 40to the housing 14 and as they roll along the raceways 58, impart theexpansions and contractions in the baring 16. Those expansions andcontractions transfer to the exterior surface 62 and to the locations ofthe sensors M along that surface 62.

In one embodiment, each sensor module M includes (FIGS. 3 & 4) a straingage 70 that basically consists of a carrier matrix 72 and two foilresistance elements 74 and 76. It should be noted that while thedescription of this embodiment describes the use of bonded resistancestrain gauge sensors which operate by changing resistance values, othertypes of strain sensors such as mechanical sensors, photoelectricsensors, optical sensors, capacitance sensors, inductance sensors, andsemiconductor sensors are also equally suitable. In this embodiment,however, the carrier matrix 72 is formed from a suitable polymer, suchas polyimide, that itself is capable of expanding and contracting withthe housing 14. It is bonded to the exterior surface of the housing 14with a suitable adhesive. Each foil resistance element 74 and 76 isformed from a suitable metal foil, such as constantan foil, which isbonded to the carrier matrix 72 such that is experiences the sameexpansions and contractions as the matrix 72. Each resistance element 74and 76 has several parallel legs 78 and end loops 80 connecting the endsof the adjacent legs 78. The outermost legs 78 terminate at tabs 82. Theelements 74 and 76, while both being on the matrix 72, are electricallyisolated from each other. Moreover, the legs 78 of the element 74 areoriented at 90° with respect to the legs 78 of the element 76. Theresistance of each leg 78 varies when it undergoes the expansion andcontractions experienced by the carrier matrix 72, and the resistance ofeach element 74 and 76 undergoes an even greater change in resistance,inasmuch as it consists of multiple legs 78 connected in series. Thematrix 72 electrically isolates the elements 74 and 76 from the metalhousing 14, yet transmits the minute expansions and contractions of thehousing 14 to the legs 78 of the elements 74 and 76.

In addition to its sensor 70, each sensor module M includes atemperature compensator 84 and a terminal block 86. The temperaturecompensator 84 should operate at the same temperature as the sensor 70,and to this end, should be located on the housing 14 adjacent to thesensor 70, even on the carrier matrix 72 of the sensor 70. In thisregard, the resistances of the resistance elements 74 and 76 not onlyvary will expansions and contractions of the matrix 72, but also withtemperature. The temperature compensator 84 is connected to theresistance elements 74 and 76, either through a bridge circuit orthrough a processor, such that it compensates or offsets changes in theresistances of the elements 74 and 76 attributable to temperaturevariations. Thus, the signals derived from the resistance elements 74and 76 reflect only variations in strain. The terminal block 86 containsterminals 88 to which the tabs 82 on the resistance elements 74 and 76are connected and to which the temperature compensator 84 is likewiseconnected, all through leads. The terminals 88 are in turn connected toa processor for evaluating and processing the signals produced by theresistance elements 74 and 76 and the temperature compensator 84.

Four sensor modules M are attached to the exterior surface 62 of thehousing 14 radially outwardly from the outboard raceway 58 and they arearranged at 90° intervals, (FIG. 5) one being with its sensor 70 at thetop of the surface 62, another with its sensor 70 at the bottom of thesurface 62 and the other two with their sensors 70 at the sides of thesurface 62. The remaining four sensor modules M are also attached to theexterior surface 62, but they are located radially outwardly frominboard raceway 58. They too are located at 90° intervals, with theirsensors 70 being at the top, bottom and sides of the surface 62. Inother words, the sensors 70 are arranged in two rows, with the sensorsin each row being located 0°, 90°, 180°, and 270°, 0° being top center.In each of the sensors 70 of the eight modules M, the legs 78 of theresistance element 74 for that sensor 70 extend circumferentially,whereas the legs 78 of the element 76 extend axially with respect to thebearing housing 14.

When the road wheel W rolls over a road surface and carries thesuspension system component C with it—as well as the entire vehicle ofwhich the component C is a part—the spindle 28 of the hub 12 rotates inthe housing 14. The cones 40 of the bearing 16, being fitted to thespindle 28 with an interference fit, likewise rotate. The taperedrollers 54 of the outboard row roll along the raceway 42 of the outboardcone 40 and the outboard raceway 58 of the housing 14. The taperedrollers 54 of the inboard row roll along the raceway 42 of the inboardcone 40 and the inboard raceway 58 of the housing 16. As the rollers 54roll between their respective raceways 42 and 58 they transfer radialloads between the cones 40 and the housing 14. The radial load exertedby any roller 54 against the outer raceway 58 along which it rollscauses the housing 14 to flex minutely, and this flexure, while existingat the raceway 58, transfers through the housing 14 to the exteriorsurface 62 and manifests itself as a slight circumferential, andsomewhat smaller, axial elongation of the surface 62 radially outwardlyfrom the line of contact between the roller 54 and the raceway 58. Thus,each time a loaded roller 58 passes between a sensor 70 and the axis X,the flexure that occurs along its raceway 58 is transmitted to theexterior surface 62 at the sensor 70 where it elongates the parallellegs 78 of the resistance element 74 for sensor 70 and increases theresistance of the resistance element 76. The magnitude of the change inresistance depends on the load, for a roller which bears against itsraceway 58 with a heavy force will impart a greater flexure than onewhich bears with a lesser force. By comparing the flexure—and thus theroller loads—reflected in the signals from the sensors 70, one canascertain conditions at the tire patch 6 in real time.

A modified bearing assembly B (FIG. 6) is the same as bearing assembly Ain all respects, except the location and orientation of the sensors 70for the eight sensor modules M. The bearing assembly B has its sensormodules M located along and attached to the outside flange surface 65 ofthe flange 64 of the housing 14. FIG. 7 shows an unfolded view of thepositions and orientations of the sensors 70 along the outside flangesurface 65. Four of the sensor modules M have their sensors 70 locatedat 0°, 90°, 180°, and 270° around the outside flange surface 65, withthe very top of the outside flange surface 65 being 0°. These sensors 70have the legs 78 of their resistance elements 74 extendedcircumferentially and the legs 78 of their resistance elements 76extended axially with respect to the housing. The remaining four sensormodules M have their sensors 70 located at 25°, 65°, 155°, and 295° fromtop center, measuring forwardly and then around. The legs 78 of theresistance elements 74 and 76 in the remaining sensors 70 are orientedat 45° with respect to the circumferential direction and likewise 45°with respect to the axial direction.

Another modified bearing assembly D (FIG. 8) also resembles the bearingassembly A in every respect except the location of the sensors 70 forthe eight sensor modules M. The bearing assembly D has its sensormodules M located along and attached to the intervening surface 59 thatlies between the two raceways 58 of the housing 14. FIG. 7 shows anunfolded view of the positions and orientations of the sensors 70 alongthe source 59. Four of the sensor modules M have their sensors 70located at 0°, 90°, 180°, and 270° around the surface 59, with the verytop of the surface 59 being 0°. These sensors 70 have the legs 78 oftheir resistance elements 74 extended circumferentially and the legs 78of their resistance elements 76 extended axially with respect to thehousing. The remaining four sensor modules M have their sensors 70located at 25°, 65°, 155° and 295° from top center, measuring forwardlyand then around. The legs 78 of the resistance elements 74 and 76 in theremaining sensors 70 are oriented at 45° with respect to thecircumferential direction and likewise 45° with respect to the axialdirection. In short, the location of the sensors 70 along theintervening surface 59 corresponds to the location of the sensors 70along the flange surface 65 of the bearing assembly B, and basically,the same holds true with respect to the orientation of the resistanceelements 74 and 76 of the sensors 70 (FIG. 7).

Another embodiment resembles the bearing assembly A in every respectexcept there is not road wheel W, rim 2, or hub 12. Instead, the bearingassembly A is mounted to any rotating shaft installation and the bearingsensors are thereafter used to provide electrical signals indicative ofthe circumferential, circumferential-axial, axial torque, and shearstrains on the bearing generally. Examples of applications which wouldneed such information are process controls for rolling mills and processcontrols for machine tools. It will be obvious to one skilled in the artof bearing design and bearing use that there are many other applicationswherein the loading sustained by a bearing would require the use of abearing capable of providing electrical signals for monitoring thosebearing loads.

1. In combination with an automotive road wheel and an automotivesuspension system component, a bearing assembly for coupling the roadwheel to the suspension system component so that the road wheel canrotate relative to the suspension system component about an axis ofrotation while providing monitoring capabilities for bearing loading,said bearing assembly comprising: a hub including a flange and a spindleprojecting from the flange, with its axis being the axis of rotation,the spindle having first and second inner raceways on it, with theraceways being presented outwardly away from the axis; a housingsurrounding the spindle of the inner race and having first and secondouter raceways presented inwardly toward and surrounding the first andsecond raceways, respectively; rolling elements arranged in first andsecond rows between the first and second raceways, respectively, andcontacting the raceways to transfer both radial and axial loads betweenthe housing and spindle; and at least four first strain sensors locatedon the housing to measure circumferential strains and circumferentialstrains less axial strains, the at least four sensors being located onthe housing such as to provide a series of signals, the signals beingcapable of providing information allowing the calculating of loads forat least four degrees of freedom.
 2. The combination according to claim1 wherein one of the sensors being at the top of the housing, another atthe bottom of the housing and others at the sides of the housing; thewheel being attached to the flange of the hub and the housing beingattached to the suspension system component, whereby the bearingassembly couples the road wheel to the suspension system component andmonitors forces transferred between the wheel and suspension systemcomponent.
 3. The combination according to claim 2 wherein the firstsensors located at the top, bottom and sides of the housing are orientedto detect strains in the circumferential direction in the housing. 4.The combination according to claim 3 wherein the first sensors arelocated on the housing around one of the outer raceways; and wherein thecombination further comprises four second strain sensors located on thehousing around the second outer raceway, with one of the second sensorsbeing at the top of the housing, another at the bottom of the housingand the others at the sides of the housing.
 5. The combination accordingto claim 4 wherein the raceways are tapered and the rolling elements aretapered rollers.
 6. The combination according to claim 2 wherein thehousing has a flange which projects outwardly, wherein the bearingassembly is attached to the suspension system component at the flange,and wherein the first sensors are located on the flange.
 7. Thecombination according to claim 6 wherein the first sensors are orientedto detect stain in the circumferential direction; and additional sensorsattached to the flange and being offset circumferentially from the firstsensors, the additional sensors being oriented to detect strains obliqueto the circumferential direction.
 8. The combination according to claim7 wherein the additional sensors are oriented at a 45 degree angle withrespect to the circumferential direction of the housing.
 9. Thecombination according to claim 7 wherein one of the additional sensorsis located between the top first sensor and one of the side firstsensors, another of the additional sensors is located between the topfirst sensor and the other side first sensor; and still another of theadditional sensors is located between one of the side sensors and thebottom sensor.
 10. The combination according to claim 9 where yetanother additional sensor is located between the top first sensor andone of the side first sensors so that two additional sensors are locatedbetween the top sensor and said one side sensor.
 11. The combinationaccording to claim 2 wherein the housing has an intervening surfacelocated between the outer raceways, and the first sensors are located onthe intervening surface.
 12. The combination according to claim 11wherein the first sensors are oriented to detect strains in thecircumferential direction; and wherein the combination further comprisesadditional sensors attached to the intervening surface and being offsetcircumstantially from the first sensors, the additional sensors beingoriented to detect strains oblique to the circumferential direction. 13.The combination according to claim 12 wherein the additional sensors areoriented at a 45 degree angle with respect to the circumferentialdirection of the housing.
 14. The combination according to claim 12wherein one of the additional sensors is located between the top firstsensor and one of the side first sensors, another of the additionalsensors is located between the top first sensor and the other side firstsensor; and still another of the additional sensors is located betweenone of the side sensors and the bottom sensor.
 15. The combinationaccording to claim 14 wherein yet another additional sensor is locatedbetween the top first sensor and one of the side first sensors, so thattwo additional sensors are located between the top sensor and side oneside sensor.
 16. A bearing assembly for facilitating rotation about anaxis and the monitoring of bearing loads, said bearing assemblycomprising: an inner race having first and second inner racewayspresented outwardly away from the axis; a housing surrounding the innerrace and having first and second raceways presented inwardly toward andsurrounding the first and second inner raceways, respectively; firstrolling elements arranged in a row between and contacting the firstraceways and second rolling elements arranged in a row between andcontacting the second raceways, whereby the inner race will rotate withminimal friction in the outer races and the rolling elements will rollalong the raceways; first sensors located around the housing radiallyoutwardly from the first outer raceway to detect strains in the housingoutwardly from the first outer raceway; second sensors located aroundthe housing radially outwardly from the second outer raceway to detectstrains on the housing outwardly from the second outer raceway; and theat least four sensors being located on the housing such as to provide aseries of signals, the series of signals being capable of providinginformation allowing the calculating of loads for at least four degreesof freedom.
 17. A bearing assembly according to claim 16 wherein firstand second sensors are attached to the housing at the top of thehousing, more first and second sensors are attached to the housing atthe bottom of the housing, and still more first and second sensors areattached to the housing at the sides of the housing.
 18. A bearingassembly according to claim 17 wherein the sensors are oriented todetect strains in the circumferential direction.
 19. A bearing assemblyaccording to claim 17 wherein the sensors are oriented to detect obliquestrains.
 20. A bearing assembly according to claim 17 wherein thesensors are oriented to detect circumferential strains less axialstrains.
 21. A bearing assembly for facilitating rotation about an axisand the monitoring of loads; said bearing assembly comprising: an innerrace having first and second inner raceways presented outwardly awayfrom the axis; a housing surrounding the inner race and having first andsecond raceways presented inwardly toward the surrounding the first andsecond inner raceways, respectively; first rolling elements arranged ina row between and contacting the first raceways and second rollingelements arranged in another row between and contacting the secondraceways, whereby the inner race will rotate with minimal friction inthe outer race and the rolling elements will roll along the raceways;and sensors attached to the housing outwardly from the outer raceways todetect strains in the housing, each sensor having an axis along which itis sensitive to dimensional changes, some of the sensors being orientedwith their axes extended in the circumferential direction to detectstrains in that direction, and others of the sensors being oriented withtheir axis oblique to the circumferential direction to detect obliquestrains, the sensors being located on the housing such as to provide aseries of signals, the series of signals being capable of providinginformation allowing the calculating of loads for at least four degreesof freedom.
 22. A bearing assembly according to claim 21 wherein thesensors are arranged in a circumferentially extending row.
 23. A bearingassembly according to claim 22 wherein the housing has a flange whichends outwardly, and the sensors are on the flange.
 24. A bearingassembly according to claim 23 wherein the housing has an interveningsurface between the outer raceways, and the sensors are on theintervening surface.
 25. A method of evaluating the conditions thatexist at a tire contact patch between a tire of a road wheel and a roadsurface, comprising the following steps: a. attaching a road wheel to ahub having a spindle that rotates about an axis and in a housing that isattached to a suspension system component of an automotive vehicle, thespindle having first and second inner raceways on it, with the racewaysbeing presented outwardly away from the axis and inclined in oppositedirections with respect to the axis, the housing having first and secondouter raceways that surround the first and second inner raceways,respectively, there being first rolling elements located in a rowbetween the second raceways, so that when rotation is imparted to thewheel, the first and second rolling elements will roll along the firstand second raceways, respectively; b. monitoring the stains in thehousing at multiple locations; c. measuring stains in the housing atmultiple locations; d. emitting signals related to the strains measured;and e. calculating the loads for five degrees of freedom, saidcalculations being made based on the stains measured.
 26. The methodaccording to claim 25 further comprising the step of monitoring thestrains which are in the circumferential, axial, and oblique directionfrom the axis.
 27. The method according to claim 26 further comprisingthe step of monitoring the stains in the circumferential, axial, andoblique direction from the axis by detecting signals from at least foursensors located at a top of the housing, at a bottom of the housing, andat each side of the housing.
 28. The method according to claim 26further comprising the step of monitoring the strains in thecircumferential, axial, and oblique direction from the axis by detectingsignals from at least four sensors located on a flange surface of thehousing at a top of the flange surface, at a bottom of the flangesurface, and at each side of the flange surface.
 29. The methodaccording to claim 26 further comprising the step of monitoring thestains in the circumferential, axial, and oblique direction from theaxis by detecting signals from at least four sensors located at a topedge of a flange of the housing, at a bottom edge of the flange of thehousing, and at each side edge of the flange of the housing.
 30. Themethod according to claim 25 further comprising the step of monitoringthe strains in the circumferential, axial, and oblique direction fromthe axis by detecting signals a series of sensors located in a singlerow around the housing.
 31. The method according to claim 25 furthercomprising the step of monitoring the strains from a series of sensorslocated along an intervening surface that lies between the first andsecond outer raceways.
 32. The method according to claim 25 furthercomprising the step of monitoring the strains from a series of sensorslocated on the housing, said series of sensors being oriented at a 45degree angle with respect to the circumferential direction of thehousing.
 33. In combination with a component for the suspension systemof an automotive vehicle and a road wheel for the vehicle, with the roadwheel being located adjacent to the suspension component, a bearingassembly for coupling the road wheel to the suspension component toenable the road wheel to rotate about an axis and to transfer loadsbetween the road wheel and suspension component, all while detectingforces that reflect conditions where the wheel contacts a road, thebearing assembly comprising: a hub to which the road wheel is secured,the hub having a spindle located along the axis; first and second innerraceways carried by the spindle of the hub, the inner raceways beingpresented outwardly away from the axis; a housing located around theinner raceways and having circumferentially and generally axiallydirected exterior and interior surfaces that are presented outwardlyaway from and inwardly toward the axis and a flange which projectsoutwardly away from the circumferentially and axially directed exteriorsurface, the housing being secured to the suspension component at itsflange, the circumferentially and axially directed exterior and interiorsurfaces and the flange together providing a sensing surface on thehousing; first and second outer raceways carried by the housing andpresented inwardly toward the axis and the inner raceways, with thefirst outer raceway being presented toward as the first inner racewayand the second outer raceway being presented toward the same directionas the second inner raceway; first rolling elements arranged in a rowbetween and contacting the first raceways and second rolling elementsarranged in a row between and contacting the second raceways, wherebythe hub will rotate with minimal friction in the housing and theindividual rolling elements will roll along the raceways to transferbetween the housing and hub radial loads and thrust loads in both axialdirections and impart to the housing strains that are reflected inflexures along the sensing surface; and strain sensors located atmultiple locations along the housing, the strain sensors beingconfigured and oriented to detect strains along the housing in at leastone axial, circumferential and oblique direction.
 34. The combinationaccording to claim 33 further comprising modules located at multiplelocations along the sensing surface of the housing, and wherein at leastsome of the strain sensors are located in the modules.
 35. Thecombination according to claim 34 wherein each module includes atemperature compensator.
 36. The combination according to claim 33wherein the strain sensors are located in modules that are attached tothe sensing surface and some of the modules have their strain sensorsoriented obliquely to detect shear.
 37. The combination according toclaim 33 wherein at least some of the strain sensors are located along acircumferentially and axially directed surface of the housing that ispresented outwardly away from the axis.
 38. The combination according toclaim 33 wherein at least some of the strain sensors are located along acircumferentially and axially directed surface of the housing that ispresented inwardly toward the axis.
 39. The combination according toclaim 33 wherein at least some of the strain sensors are located on theflange of the housing.
 40. The combination according to claim 33 whereinat least some of the strain sensors are located on the housing at 0°,90°, 180° and 270° with respect to the vertical.
 41. The combinationaccording to claim 40 wherein the strain sensors that are located at 0°,90°, 180° and 270° are oriented to detect strains in both thecircumferential and axial directions.
 42. The combination according toclaim 41 wherein at least one more sensor is circumferentially offsetwith respect to the strain sensors located at 0°, 90°, 180° and 270°wherein the at least one more sensor senses shear.
 43. The combinationaccording to claim 42 wherein the offset sensor senses strains obliqueto the circumferential and axial directions.
 44. In combination with acomponent for the suspension system of an automotive vehicle and a roadwheel for the vehicle, with the road wheel being located adjacent to thesuspension component, a bearing assembly for coupling the road wheel tothe suspension component to enable the road wheel to rotate about anaxis and to transfer loads between the road wheel and suspensioncomponent, all while detecting forces that reflect conditions where thewheel contacts a road, the bearing assembly comprising: a hub to whichthe road wheel is secured, the hub having a spindle located along theaxis; first and second inner raceways carried by the spindle of the hub,the inner raceways being presented outwardly away from the axis; ahousing located around the inner raceways and having circumferentiallyand generally axially directed exterior and interior surfaces that arepresented outwardly away from and inwardly toward the axis and a flangewhich projects outwardly away from the circumferentially and axiallydirected exterior surface, the housing being secured to the suspensioncomponent at its flange, the circumferentially and axially directedexterior and interior surfaces and the flange together providing asensing surface on the housing; first and second outer raceways carriedby the housing and presented inwardly toward the axis and the innerraceways, with the first outer raceway being presented toward the samedirection as the first inner raceway and the second outer raceway beingpresented toward the same direction as the second inner raceway; firstrolling elements arranged in a row between and contacting the firstraceways and second rolling elements arranged in a row between andcontacting the second raceways, whereby the hub will rotate with minimalfriction in the housing and the individual rolling elements will rollalong the raceways to transfer between the housing and hub radial loadsand thrust loads in both axial directions and impart to the housingstrains that are reflected in flexures along the sensing surface; andmodules located at multiple locations along the sensing surface of thehousing, the modules having strain sensors which are configured andoriented to detect strains along the sensing surface in circumferentialand axial directions and to detect strains in directions oblique to thecircumferential and axial directions.
 45. The combination according toclaim 44 wherein at least some of the strain sensors are located on thehousing at 0°, 90°, 180° and 270° with respect to the vertical.
 46. Thecombination according to claim 45 wherein the strain sensors that arelocated at 0°, 90°, 180° and 270° are oriented to detect strains in boththe circumferential and axial directions.
 47. The combination accordingto claim 46 wherein at least one more sensor is circumferentially offsetwith respect to the strain sensors located at 0°, 90°, 180° and 270°wherein the at least one more sensor senses shear.
 48. The combinationaccording to claim 47 wherein the offset sensor senses strains obliqueto the circumferential and axial directions.
 49. The combinationaccording to claim 44 wherein the strain sensors are located on thesensing surface adjacent to the suspension component, the suspensioncomponent influences strain distribution within the housing of thebearing such that the sensors measure the distributed strains.
 50. Thecombination according to claim 49 wherein the suspension componentcomprises a brake.
 51. The combination according to claim 44 wherein atleast some of the sensors are located on a flange surface of the flangeof the housing.
 52. The combination according to claim 44 wherein thehousing has an intervening surface located between the outer racewaysand the strain sensors are located on the intervening surface.
 53. Thecombination according to claim 52 wherein the strain sensors which arelocated on the intervening surface correspond to the positions of thestrain sensors located along the flange surface.
 54. The combinationaccording to claim 44 wherein the strain sensors are located along thesensing surface for measuring strains applied to the housing for eachdegree of freedom of the road wheel.
 55. The combination according toclaim 44 wherein the strain sensors comprise strain gages.
 56. A methodof evaluating results from modules disposed on a housing of a bearing,the results relating to a suspension component of an automotive vehicleand a road wheel for the vehicle, with the road wheel being locatedadjacent to the suspension component, a bearing assembly for couplingthe road wheel to the suspension component to enable the road wheel torotate about an axis and to transfer loads between the road wheel andsuspension component, all while detecting forces that reflect conditionswhere the wheel contacts a road, the method comprising: attaching theroad wheel to a hub of the suspension component, the hub having aspindle located along an axis and in the housing that is attached to thesuspension component, with first and second inner raceways carried bythe spindle of the hub, the inner raceways being presented outwardlyaway from the axis and, with respect to the axis; the housing beinglocated around the inner raceways and having circumferentially andgenerally axially directed exterior and interior surfaces that arepresented outwardly away from and inwardly toward the axis and a flangewhich projects outwardly away from the circumferentially and axiallydirected exterior surface, the housing being secured to the suspensioncomponent at its flange, the circumferentially and axially directedexterior and interior surfaces and the flange together providing asensing surface on the housing; first and second outer raceways carriedby the housing and presented inwardly toward the axis and the innerraceways, with the first outer raceway being presented toward andinclined in the same direction as the first inner raceway and the secondouter raceway being presented toward and inclined in the same directionas the second inner raceway; first rolling elements arranged in a rowbetween and contacting the first raceways and second rolling elementsarrange in a row between and contacting the second raceways, whereby thehub will rotate with minimal friction in the housing and the individualrolling elements will roll along the raceways to transfer between thehousing and hub radial loads and thrust loads in both axial directionsand impart to the housing strains along the sensing surface; positioningmodules at multiple locations along the housing, the modules havingstrain sensors which are configured and oriented for detecting strainsalong the housing in at least one axial, circumferential and obliquedirection; monitoring the strain sensors in the housing at the multiplelocations; and measuring the strains detected by the strain sensorswherein the modules calculate loads applied to the housing based on thedetected strains.
 57. The method according to claim 56 wherein detectingthe strains along the housing comprises detecting strains along thesensing surface in circumferential and axial directions and detectingstrains in directions oblique to the circumferential and axialdirections.
 58. The method according to claim 56 wherein positioning themodules comprises orientating the sensors obliquely on the housing todetect shear.
 59. The method according to claim 56 wherein positioningthe modules comprises locating the strain sensors on the flange of thehousing.